Hi Cathy!
You have a tough choice to make as they are both wonderful! A couple of things you should consider is price and location.
Disney's Beach Club Resort is priced as a Deluxe Resort and
Disney's Caribbean Beach Resort is priced as a Moderate Resort. The difference in price can be significant. As for location, I really like Disney's Beach Club. It is located next to Epcot (literally within walking distance) and can even be accessed through a smaller entrance located near the World Showcase. I find this very convenient if you wish to dine at the many restaurants in Epcot. Although the dates have not been released yet, you visit may coincide with
Epcot International Food & Wine Festival, which would definitely make you want to stay closer to Epcot!
As for the balcony, there are no balconies at Disney's Caribbean Beach. The buildings are two story buildings with open air corridors or walkways. You can get a balcony at Disney's Beach Club.
Personally, I visited each one of these resorts when my kids were about the same age as yours. While they loved the Pirates room offered in Disney's Caribbean Beach Resort, they enjoyed Disney's Beach Club even more! You can't top the pool at Disney's Beach Club known as
Stormalong Bay (and is full of beach sand for them to play with). Beaches and Cream Soda Shop also located here was their absolute favorite!
It has been a pleasure assisting you Cathy. Please feel free to send me another other question you may have.
Thanks for sending your questions to the Disney Parks Moms Panel.
Yael